Dissipation mechanisms of excess photon energy under high-temperature stress were studied in a subtropical forest tree seedling, Ficus concinna. Net CO2 assimilation rate decreased to 16% of the control after 20 d hig...Dissipation mechanisms of excess photon energy under high-temperature stress were studied in a subtropical forest tree seedling, Ficus concinna. Net CO2 assimilation rate decreased to 16% of the control after 20 d high-temperature stress, and thus the absorption of photon energy exceeded the energy required for CO2 assimilation. The efficiency of excitation energy capture by open photosystem Ⅱ（PSⅡ） reaction centres （Fv＇/Fm＇） at moderate irradiance, photochemical quenching （qp）, and the quantum yield of PSII electron transport （φPSⅡ） were significantly lower after high-temperature stress. Nevertheless, non-photochemical quenching （qNP） and energy-dependent quenching （qE） were significantly higher under such conditions. The post-irradiation transient of chlorophyll （Chl） fluorescence significantly increased after the turnoff of the actinic light （AL）, and this increase was considerably higher in the 39 ℃-grown seedlings than in the 30 ~C-grown ones. The increased post-irradiation fluorescence points to enhanced cyclic electron transport around PSI under high growth temperature conditions, thus helping to dissipate excess photon energy non-radiatively.展开更多
The aim of this study was to enhance the solubility and stability of Acacia concinna extract by loading in a microemulsion for topical application. Both physical appearance and biological activities of the extract-loa...The aim of this study was to enhance the solubility and stability of Acacia concinna extract by loading in a microemulsion for topical application. Both physical appearance and biological activities of the extract-loaded microemulsion were determined in comparison with the extract solution. Pseudoternary phase diagrams of three oil types including tea seed oil, grape seed oil, and sesame oil, together with polysorbate 85 or the mixture of polysorbate 85 and sorbitan oleate as surfactants, and absolute ethanol as a co-surfactant were constructed to optimize the microemulsion area. The selected microemulsion was then characterized for droplet size, polydispersity index, and viscosity. Tea seed oil exhibited the highest microemulsion area in the phase diagram because it had the highest unsaturated fatty acid content. The microemulsion composed of tea seed oil(5%), polysorbate 85(40%), ethanol(20%), and water(35%) exhibited Newtonian flow behavior with the droplet size and polydispersity index of 68.03 ± 1.09 nm and 0.44 ± 0.04, respectively. After 4% w/w of the extract was incorporated into the microemulsion, larger droplets size was observed(239.77 ± 12.69 nm)with a lower polydispersity index(0.37 ± 0.02). After storage in various conditions, both physical appearances and the stability of biological activity of the extract-loaded microemulsion were improved compared to the solution. Therefore, the A. concinna loaded microemulsion may be a promising carrier for further development into a topical formulation and clinical trials for pharmaceutical and cosmeceutical applications are also suggested.展开更多
Backgroud:Coltiviruses are spherical,non-enveloped viruses with 12 double-stranded RNA segments,belonging to the family Spinareoviridae,and predominantly transmitted by ticks.This study isolated and characterized a no...Backgroud:Coltiviruses are spherical,non-enveloped viruses with 12 double-stranded RNA segments,belonging to the family Spinareoviridae,and predominantly transmitted by ticks.This study isolated and characterized a novel coltivirus,designated Woodland tick reovirus(WLTRV),from Haemaphysalis concinna ticks collected in Helong City,Jilin Province,in Northeastern China.Methods SW-13 and Vero cells were used to isolate WLTRV through three blind passages,while seven mammalian cell lines assessed viral growth.Viral morphology was observed by electron microscopy.Next-generation sequencing,5ʹand 3ʹrapid amplification of cDNA ends were used to determine WLTRV whole genome sequences,and phylogenetic methods were used to characterize WLTRV.A real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect WLTRV RNA in ticks.Results:WLTRV grew and exerted cytopathic effects in human(SW-13 and 293T)and mouse(BHK-21 and N2A)cell lines,revealing its potential to infect mammals.Phylogenetic analysis based on RNA-dependent RNA polymerase sequences classified WLTRV within the genus Coltivirus,with a close evolutionary relationship to Tarumizu tick virus.The nucleotide and amino acid sequence homologies between WLTRV and Tarumizu tick virus across the 12 segments analyzed ranged from approximately 44.79%to 69.09%and 33.73%to 75.60%,respectively.WLTRV shared conserved the 5ʹ-terminal(GACAA/UU/A)and 3ʹ-terminal(UGCAGUC)consensus sequences of the genus Coltivirus genomes.Electron microscopy revealed WLTRV as spherical(diameter∼80 nm),non-enveloped,and morphologically consistent with coltiviruses.Among the 4,717 ticks collected from six towns in the Yanbian Korean Autonomous Prefecture,WLTRV RNA was only detected in H.concinna(0.95%virus-carrying rate)but not in Haemaphysalis japonica,Haemaphysalis longicornis,Ixodes persulcatus,and Dermacentor silvarum.Conclusions:This study represents the first isolation and identification of WLTRV from H.concinna in the Yanbian Korean Autonomous Prefecture,providing new insights into the genetic diversity and evolution of the genus Coltivirus.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province, China (No. Y3090276)the Major Program of Science and Technology Department of Zhejiang Province, China (No. 2007C12023)the Scientific Research Foundation for PhD of Zhejiang Forestry University, China (No. 2007FR047)
文摘Dissipation mechanisms of excess photon energy under high-temperature stress were studied in a subtropical forest tree seedling, Ficus concinna. Net CO2 assimilation rate decreased to 16% of the control after 20 d high-temperature stress, and thus the absorption of photon energy exceeded the energy required for CO2 assimilation. The efficiency of excitation energy capture by open photosystem Ⅱ（PSⅡ） reaction centres （Fv＇/Fm＇） at moderate irradiance, photochemical quenching （qp）, and the quantum yield of PSII electron transport （φPSⅡ） were significantly lower after high-temperature stress. Nevertheless, non-photochemical quenching （qNP） and energy-dependent quenching （qE） were significantly higher under such conditions. The post-irradiation transient of chlorophyll （Chl） fluorescence significantly increased after the turnoff of the actinic light （AL）, and this increase was considerably higher in the 39 ℃-grown seedlings than in the 30 ~C-grown ones. The increased post-irradiation fluorescence points to enhanced cyclic electron transport around PSI under high growth temperature conditions, thus helping to dissipate excess photon energy non-radiatively.
基金supported by Agricultural Research Development Agency (public organization)ARDA [grant number CRP5705011620]
文摘The aim of this study was to enhance the solubility and stability of Acacia concinna extract by loading in a microemulsion for topical application. Both physical appearance and biological activities of the extract-loaded microemulsion were determined in comparison with the extract solution. Pseudoternary phase diagrams of three oil types including tea seed oil, grape seed oil, and sesame oil, together with polysorbate 85 or the mixture of polysorbate 85 and sorbitan oleate as surfactants, and absolute ethanol as a co-surfactant were constructed to optimize the microemulsion area. The selected microemulsion was then characterized for droplet size, polydispersity index, and viscosity. Tea seed oil exhibited the highest microemulsion area in the phase diagram because it had the highest unsaturated fatty acid content. The microemulsion composed of tea seed oil(5%), polysorbate 85(40%), ethanol(20%), and water(35%) exhibited Newtonian flow behavior with the droplet size and polydispersity index of 68.03 ± 1.09 nm and 0.44 ± 0.04, respectively. After 4% w/w of the extract was incorporated into the microemulsion, larger droplets size was observed(239.77 ± 12.69 nm)with a lower polydispersity index(0.37 ± 0.02). After storage in various conditions, both physical appearances and the stability of biological activity of the extract-loaded microemulsion were improved compared to the solution. Therefore, the A. concinna loaded microemulsion may be a promising carrier for further development into a topical formulation and clinical trials for pharmaceutical and cosmeceutical applications are also suggested.
基金supported by the Beijing Natural Science Foundation(No.L232069)the National Key R&D Program of China(No.2022YFC2302700)the Young Scholar Science Foundation of China CDC(No.2023A103).
文摘Backgroud:Coltiviruses are spherical,non-enveloped viruses with 12 double-stranded RNA segments,belonging to the family Spinareoviridae,and predominantly transmitted by ticks.This study isolated and characterized a novel coltivirus,designated Woodland tick reovirus(WLTRV),from Haemaphysalis concinna ticks collected in Helong City,Jilin Province,in Northeastern China.Methods SW-13 and Vero cells were used to isolate WLTRV through three blind passages,while seven mammalian cell lines assessed viral growth.Viral morphology was observed by electron microscopy.Next-generation sequencing,5ʹand 3ʹrapid amplification of cDNA ends were used to determine WLTRV whole genome sequences,and phylogenetic methods were used to characterize WLTRV.A real-time quantitative polymerase chain reaction(RT-qPCR)was used to detect WLTRV RNA in ticks.Results:WLTRV grew and exerted cytopathic effects in human(SW-13 and 293T)and mouse(BHK-21 and N2A)cell lines,revealing its potential to infect mammals.Phylogenetic analysis based on RNA-dependent RNA polymerase sequences classified WLTRV within the genus Coltivirus,with a close evolutionary relationship to Tarumizu tick virus.The nucleotide and amino acid sequence homologies between WLTRV and Tarumizu tick virus across the 12 segments analyzed ranged from approximately 44.79%to 69.09%and 33.73%to 75.60%,respectively.WLTRV shared conserved the 5ʹ-terminal(GACAA/UU/A)and 3ʹ-terminal(UGCAGUC)consensus sequences of the genus Coltivirus genomes.Electron microscopy revealed WLTRV as spherical(diameter∼80 nm),non-enveloped,and morphologically consistent with coltiviruses.Among the 4,717 ticks collected from six towns in the Yanbian Korean Autonomous Prefecture,WLTRV RNA was only detected in H.concinna(0.95%virus-carrying rate)but not in Haemaphysalis japonica,Haemaphysalis longicornis,Ixodes persulcatus,and Dermacentor silvarum.Conclusions:This study represents the first isolation and identification of WLTRV from H.concinna in the Yanbian Korean Autonomous Prefecture,providing new insights into the genetic diversity and evolution of the genus Coltivirus.
